Regular Expressions 101

Explanation

Pro

^start of line

#{1,4}the literal # (35₁₀ / 43₈ / 23₁₆) , repeated between 1 and 4 times

\sany whitespace character

Negative Lookahead(?!.*\[#.*\]$)

.*any character (except for line terminators), repeated any number of times

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

.*any character (except for line terminators), repeated any number of times

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

$end of line

.*any character (except for line terminators), repeated any number of times

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

No unit tests

Add a test to get started

25 tokens

^#{1,4}\s(?!.*\[#.*\]$).*

There are no unit tests.